Incidence and Severity of Comandra Blister Rust on Lodgepole Pine in Northwestern Wyoming. B. W. Geils, Graduate Research Assistant, Department of Plant Pathology and Weed Science, Colorado State University, Fort Collins 80523. W. R. Jacobi, Assistant Professor, Department of Plant Pathology and Weed Science, Colorado State University, Fort Collins 80523. Plant Dis. 68:1049-1051. Accepted for publication 12 May 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-1049.

A survey of the Wind River District, Shoshone National Forest, WY, was conducted in 1981–1982 to assess the incidence and severity of comandra blister rust in lodgepole pine. In the commercial forest, more than 30% of the basal area was lodgepole pine, and 50% of that was damaged by Cronartium comandrae. The average diseased tree was 107 yr old, 24 cm in diameter, 15 m tall, and growing among other lodgepole pines. The average canker was several decades old and had killed the top third of the crown. Although the rust was not found in stands less than 20 yr old, these stands may become infested.